<style type="text/css">
#contenedor {
    display: table;
    border: 2px solid #000;
    width: 300px;
    text-align: center;
    margin: 0 auto;
}
#contenidos {
    display: table-row;
}
#columna {
    display: table-cell;
    border: 1px solid #000;
    vertical-align: middle;
    padding: 10px;
     font-weight: bold
}
#columna1 {
    display: table-cell;
    border: 1px solid #000;
    vertical-align: middle;
    padding: 10px;
}

</style>